"[O'Connor] compels the reader to inhabit his characters' lives. Half World is a stunningly grim and emotionally harrowing read and an astute and evocative portrayal of government paranoia during the Cold War and Vietnam War eras.”—Booklist (starred review)

"Fascinating…O'Connor is a gifted stylist, and he vividly captures the rabbit hole that swallows agents, their families, and their victims alike." —Library Journal

"Rich in philosophy and dark in its politics, Half World is an incredibly beautiful literary thriller…quite rightly compared to some of Graham Greene's strongest works…O'Connor recaptures the illicit CIA experiments with LSD as only great fiction could dare to imagine…A glorious read.” —Weekend Bookworm, Australian Broadcasting Corporation

From its official sanction in 1953 to its shutdown in 1973, the CIA clandestinely conducted methods of mind control on unwitting American and Canadian citizens. This covert and illegal operation, Project MKUltra, eventually made national headlines upon the declassification of thousands of documents in 2001.

Inspired by these events, Scott O’Connor’s Half World is the story of Henry March, a fraying CIA analyst who conducts secret mind-control experiments in San Francisco. With each passing day, Henry’s existence becomes a nightmare, his identity withering as he works over the hapless men lured into his facility.

Struggling between his duty to his country and his responsibility to his wife and children, Henry finally reaches a breaking point, leaving both his project and mind fractured. Amid the wreckage, he becomes the deepest ULTRA mystery.

Two decades later, Dickie Ashby, a young, drug-addled CIA agent, is sent to Los Angeles to infiltrate a group of bank-robbing radicals who claim to have been abused in a government brainwashing operation years earlier. The members of the group know they need to find Henry March and Dickie suddenly finds himself dragged into the stunning legacy of the experiments, tragedy that has destroyed the March family, and which threatens to engulf a war-torn country ready to combust.